@felmue

FWIW & IMHO, Arduino is far to limiting. IDF opens up far more options that Arduino just does not address.
Menuconfig is the primary reason for me to use IDF, and like the other poster said, having many source files Arduino is just to crippling to large projects beyond twinkling a led.

I too hope M5Stack comes out with an updated official version of m5stack for IDF.

Tested with IDF 4.1 and I got a bunch of warnings, but build completed successfully!

Again, thanks @brus!

maybe you could commit a issues to the M5Stack_TreeView Github.

Since esp-idf is not directly endorsed by M5Stack, it may be better to ask on espressif forums or perhaps the esp32 reddit community